Dental engine arm



vOct.,l5, 1963 R. w. PAGE 3,106,777

DENTAL ENGINE -ARM Filed Nay.v 21. 1958 2- sheets-sheet 1 Oct. l5, 1963 R. w. PAGE 3,106,777

DENTAL ENGINE ARM l Filed Nay 21, 1958 l 2 sheets-sheet 2 RICHARD W. PAGE United States Patent O 3,106,777 DENTAL ENGINE ARM Richard W. Page, 307 Quaker Road, Chappaqua, NSY. Filed May 21, 195%, Ser. No. 736,374 14 Claims. (Cl. 32-25) This invention relates to dental engine arms.

More particularly, the invention is concerned with providing a dual engine arm equipped with two instruments, so that either instrument is available at will.

High speed drilling instruments are available and in a form permitting interchange with slower yspeed instruw ments at the hand piece or wrist-joint of the engine arm.

However, this exchange is bothersome, and where both types of instruments are used, it is desirable to have both instantly accessible. In other case-s, Ias where work is being Clo-ne alternately with two different burrs, it is also convenient to have two instruments `constantly in readiness for use.

It is `an object of the present invention to provide a dental engine in which two hand pieces or other instruments are constantly available.

Another object is to provide convenient out-of-the-way storage for whichever instrument is not in use.

Still another object is tto provide a dual arm which may be attached to existing equipment with minimum expense and complication.

An engine arm embodying the invention in a preferred form will now be described with reference tothe acc-om- -panying drawing and the features forming the invention will then be pointed out in the appended claims.

In the drawing, FIG. 1 is a somewhat `schematic side elevation o-f the dual engine arm, and EFIG. 2 is a much enlarged View of the elbow joint. l

FIG. 3 is an enlarged view of the elbow joint partly in section and FIG. 4 is a sectional view taken on the line 4 4 of FIG. 3.

The engine arm, down to the elbow joint, is almost entirely of standard construction. `It comprises a pedestal l, pivotally supporting the bracket member 2, whose lower end is attached 4to the pedestal at 3 and whose upper end carries the shoulder joint 4. The upper arm S is pivotally attached to the bracket member 2 by the shoulder joint 4 and in turn carries the elbow joint 6 to which are attached fo-rearms 7-a and 7-b. The forearm 7-a carries a high speed contra-angle drilling instrument -a, `which may be as shown in Page Patent 2,824,370 and capable of operating at speeds in excess of 100,000 rpm., while forearm "i-b 'may carry a hand piece S-b, operating at a slower speed, such, for example, as 30,000 r.p.m. The construction `of wrist-joints @-a, 9-b may be conventional.

Motor l drives a belt 11, led around pulleys at each side of the shoulder join-t and driving a pulley l2 in the elbow joint (FIG. 2). The .drive for instrument 8-1 is by means of a belt lli-a going around a pulley 13-[1 at the elbow joint (FIG. 2) and around pulleys lid-a, lS-a at the wrist-joint and the instrument. The drive for instrument -b is the same, belt )l2-b passing around similar pulleys .i3-b, 14b and lS-b.

Air and Water lines i6, 17 may be led along the bracket and arms, as usual, for one or both instruments.

The mounting of forearms 7-a, 7-b is best shown in FIGS. 2 and 3. As there indicated, the upper `arm 5 carries a tubular U-shaped elbow joint frame l, in each leg of which there is fixed a hollow shaft section 19-a, 19-b, as by means of T elements 2li-a and 20-b carrying the shaft sections and fitting in the frame 18, being secured therein as by means of set screws Zit-a and 2li-b. A central shaft 22 is slidably carried in the hollow shafts 19-a and 19-11 and carries toward its center the pulley ll by ICC means of anti-friction bearings 23 held in place by split rings 24, as indicated. The pulleys 13-a and 13-b, previously referred to, are carried on the hollow shaft sections )L9-zz and l9-b by means of antifriction bearings 25-a and Z5-b and the hubs or faces of the pulleys 13-a, 13-b and 11 are provided with cooperating clutch teeth 26, as indicated. It will be apparent that shifting shaft 22 axially will cause the clutch teeth on the pulley 1l to engage either the teeth on pulley .i3-a or those on pulley lS-b, as desired. The `forearms 7-a and 7-b terminate at the wrist joint in opposite end sections 27-a and 27-b pivotally mounted on the hollow shafts 19-a, lil-b by means of hubs ZS-a and ZS-b, the construction of which is the same except for being, respectively, right and left hand.

As shown in detail in the case of the hub 28-b, this includes a bore 29-b rotatably fitting the hollow shaft 19-b and a bearing washer .3G-b also fitting ythis shaft and held in place by the `split ring 3kb. A spring SZ-b acting `against the washer Btl-b secured to the hub 28-b and against a washer 33-b held in place on the hollow shaft 19-b by a split ring 3ft-b, serves to urge the hub outwardly along the shaft 19-12 while permitting a limited inward movement against the spring for Ithe purpose described below. A pin 3S-b passes through and is secured lto the solid shaft 22 and passes through axially extending slots 3o-b in the hollow shaft 19-b, thus permitting rela- -tive sliding movement between these members while preventing tuming. Pin 35-b is also positioned for engagement against a cam surface 37-b formed `at the outer end of the hub ZS-b, this cam being formed so that as the forearm is rotated up into inoperative position, the shaft 22 slides over, disengaging the associated pulley 13-b and permitting engagement of the pulley 13-a as later described more fully. rPhe open end of hub 28-b is covered (by a sheet metal cover t0-b which may have a snap t over the hub, so that the working parts are concealed and protected. As will be understood, the internal structure of hub 2S-a, not shown, is identical to that just described in connection with hub ZS-b, except .that `all parts are reversed left for right.

Assuming that forearm 7-a is down in an operating position and forearm 7-b has been rocked up along the upper arm 5 into inoperative position, the drive is automatically connected to forearm '7-a, since the cam surface 37-a (not shown) engaging pin 35-a will have pulled the shaft 22 over toward hub 28-a engaging the clutch teeth 26 on pulley 11 with those on pulley 13-a. The last 30 or so of movement of the arm 7-a in rocking it up into inoperative position will have brought the pin SiS-b opposite a low point on the cam surface 37-b, permitting this movement of the shaft 22. As will be understood, placing arm 7-a up against arm 5 and dropping arm 7-b shifts the shaft 22 in the opposite direction, disengaging the clutch teeth of pulley Wheel 11 from pulley wheel 13a-a and engaging them with pulley wheel 13-b.

The joints of the engine arm apparatus just described have the usual pivotal movements about the usual axes, arm 5 hinging up and down and also rotating on its own axis. However, the rotative coupling 50 for arm 5 instead of being located down toward the elbow joint which is as usual, is located up toward the shoulder joint 4, so that the arm and parts carried thereby below this point move as a unit. Hook 51 which is a double hook adapted to hold either or both arms in an inoperative position as shown, is secured to the arm S below this rotative coupling 50. Also, below the coupling 50 the tubular arm 5 has an opening 52 receiving the air and water lines 16 and 17 which pass down through the hollow arm 5 into the joint frame and thence to a valve chest 53 secured to the frame 18 and having five valve elements 54 for controlamare/7 rg .5 ling ve air and water lines. These lines may include two air lines 16 for the forearm 7-a and one water line 17 for this forearm, one of the air lines being for maintaining sealing pressure within the contra-angle head and a single air and water line 16, 17 for the other forearm 7-b.

In operation, the instrument handles just like a conventional dental engine. Assuming the parts in the position of FIG. 1, it will be apparent that the instrument S-a could be used precisely as though it were mounted in a single engine arm, the joint movements being identical. Arm 7-b being folded up against the upper arm is entirely out of the way and causes no difficulty. Pulling up arm 7-a and swinging down arm 7-b permits use of the instrument 8-b with exactly the same freedom.

It will be noted that each of the hubs ZS-a or ZS-b is mounted for a limited spring resisted movement toward the frame 18, permitting engagement of the cam surfaces 37-a and 37-b with their respective pins .3S-a and 35-b without damage to the parts. The camming movement by which the shaft 22 is actually moved is preferably caused by a fairly rapid camming action occurring through the last 30 or so and hinging up of the forearm so as to avoid damage to the clutch teeth through too gradual a disengaging movement. The limited spring resisted movement of the hub 28-a and 28-b permits both arms to be in the upper position when the engine is not in use and the pulley 11 to assume and hold a centered position under these conditions.

What is claimed is:

1. A dual dental engine arm apparatus comprising, in combination, an upper arm and two forearm assemblies hingedly joined thereto.

2. A dual dental engine arm apparatus comprising, in combination, an upper arm and two forearm assemblies hingedly joined thereto, the forearms being foldable back along the upper arm when not in use.

3. A dual dental engine arm apparatus comprising, in combination, an upper arm and two forearms hingedly joined thereto, the said forearms being foldable back along the upper arm when not in use and the upper arm comprising means for holding the forearms in folded back position.

4. A dual dental engine arm apparatus comprising, in combination, an upper arm, an elbow joint, two forearm assemblies pivotally carried by the elbow joint and drive means for selectively driving the said forearm assemblies.

5. A dual dental engine arm apparatus comprising, in combination, an upper arm, an elbow joint, two forearm assemblies pivotally carried by the elbow joint and drive means for selectively driving the said forearm assemblies, the said forearms being foldable back along the upper arm when not in use.

6. A dual dental engine arm apparatus comprising, in combination, an upper arm, an elbow joint, two forearm assemblies pivotally carried by the elbow joint and drive means for selectively driving the said forearms, the said forearms being lfoldable back along the upper arm when not in use and the drive means comprising clutch means operable by a said forearm on hinging down from folded back position to connect the said forearm drive.

7. A dual dental engine arm apparatus comprising, in combination, an upper arm, an elbow joint and two forearm assemblies pivotally carried by the elbow joint, a `belt and pulley drive comprising a pulley rotatably carried by the elbow joint and n pulley belt extending back along the upper arm vfor driving the said pulley, a pulley also rotatively carried by the elbow joint coaxial with the pivotal axis of each said forearm, and clutch means for selectively forming a driving connection from the first said pulley to the last said pulleys.

8. A dual dental engine arm apparatus according to claim 7, in which the said clutch means comprises clutch elements operable by the forearms in pivoting about their said axes.

9. A dual dental engine arm apparatus according to claim 7, in which the said clutch means comprises clutch elements/fixed to the two said forearm pulleys, a clutch memlff selectively engageable with the two said elements, and means operable by the forearms for shifting the said clutch member.

l0. A dual engine arm according to claim 7, in which the said forearms comprise offset portions adjacent the elbow joint and the forearms generally lie substantially in the plane of their said pulleys.

11. A dual dental engine arm apparatus comprising, in combination, an upper arm, two forearms and an elbow joint hingedly joining the said forearms to the upper arm, the said forearms being foldable back along the upper arm when not in use, the upper arm comprising means for holding the forearms in folded back position and comprising also a rotative coupling positioned above the last said means for providing pivotal movement of the elbow joint about the axis of the upper arm.

12. A dual dental engine arm apparatus according to claim 11, in which the upper arm is tubular and comprising air and water hose connections contained within the said upper arm.

13. A dual dental engine arm apparatus comprising, in combination, a tubular upper arm and two `forearm assemblies hingedly joined thereto, and air and water hose connections for the two said forearms contained within the said tubular upper arm.

14. A dual dental engine arm apparatus comprising, in combination, a tu-'bular upper arm, an elbow joint frame fixed to the upper arm, a pair of forearms pivotallyI carried by the elbow joint frame, a valve box fixed to the said frame, air and water hose connections in the tubular upper arm and hollow elbow joint frame leading to the said valve box and air and water hose connections from the said valve box to the said forearms.

Neel Nov. 30, 1920 Cunningham Mar. 2, 1948 

1. A DUAL DENTAL ENGINE ARM APPARATUS COMPRISING, IN COMBINATION, AN UPPER ARM APPARATUS COMPRISING, IN HINGEDLY JOINED THERETO. 